Configuration Details:

Colon (:) or comma (,) separated list of SSL implementation options
to use when proxying https:// URLs
The most important being:
NO_SSLv2 Disallow the use of SSLv2
NO_SSLv3 Disallow the use of SSLv3
NO_TLSv1 Disallow the use of TLSv1.0
NO_TLSv1_1 Disallow the use of TLSv1.1
NO_TLSv1_2 Disallow the use of TLSv1.2
SINGLE_DH_USE
Always create a new key when using temporary/ephemeral
DH key exchanges
NO_TICKET
Disable use of RFC5077 session tickets. Some servers
may have problems understanding the TLS extension due
to ambiguous specification in RFC4507.
ALL Enable various bug workarounds suggested as "harmless"
by OpenSSL. Be warned that this may reduce SSL/TLS
strength to some attacks.
See the OpenSSL SSL_CTX_set_options documentation for a
complete list of possible options.
WARNING: This directive takes a single token. If a space is used
the value(s) after that space are SILENTLY IGNORED.